Posted by: akolk | January 30, 2009

Stability is your friend

Oracle and other Microsoft are putting more and more automatic and self – everything features into their database. There are of course many reasons why that makes sense (for Oracle and Microsoft), but does it make sense for all Oracle Systems and their DBAs? I don’t think so. Consider this:

All these automatic and self-tuning features will manage resources and make decisions that can and will change the behavior of your system. Now consider that you are the DBA of a mission critical Oracle system. Do you want  a system that runs good enough and stable or do you want a system that sometimes runs perfect and sometimes runs badly? Let me know.


  1. Well, i like diagnostic tools, but not self-tuning. I like to know that my system will behave the same in the time, so i prefer a system that runs good enough and stable.
    i think this is a problem of us geek people 🙂

  2. Blogged about precisely this not too long ago.
    I don’t want a system that “self-tunes” like a yo-yo every few minutes!

    If this type of feature was designed and written by someone with minimal knowledge of engineering, they’d know about positive feedback and what it can do to any closed loop feedback system.

    Unfortunately, it’s being written by code-happy duhvelopers paid by the ton of lines…

  3. Irrespective of the pros and cons of automatic tuning, the tools that come with Oracle, certainly with 10g release 2, omit to provide recommendations on a lot of things:-

    1. When to use index compression

    2. Relocating larger more frequently accessed indexes to tablespaces with larger block sizes for index range scan intensive applications.

    3. Using IOTs when only a small proportion of a tables rows are frequently accessed and most of the tables columns appear in the from clause.

    4. That segment auto free space management has an adverse affect on index clustering factors.

    5. Recommendations around bad schema design, one to one relationships,designs conduscive to “walking with keys”, i.e. in order to join tables a to e, you have to go via b, c, d in order to pickup key values.

    etc . . .

    I have not played around with 11g as extensively as I have with 10g release 2, suffice it to say I would be surprised if this situation has changed that much with 11g.


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